Ski and ski practice machine

ABSTRACT

A ski is provided on its under surface with a longitudinal central part having a smoother surface configuration than the adjacent surfaces and this ski is to be used on a substantially hard smooth surface especially on an inclined belt which can be adjusted as to speed and inclination.

United States Patent 1191 Catlin 1 June 4, 1974 I SKI AND SKI PRACTICE MACHINE [75] Inventor: William Paul Catlin,

Knaresborough, England [73] Assignee: Mogul Leisure Products Limited,

Knaresborough, Yorkshire, England [22] Filed: Aug. 7, 1972 [21] Appl. No.: 278,589

[30] Foreign Application Priority Data Aug. 20, 1971 Great Britain... 18844/1 Aug. 22, 1972 Great Britain 3122/72 [52] US. Cl 272/565 SS, 280/11.13 S

[51] Int. Cl A63g 21/00 [58] Field of Search ..280/11.13 S, 11.13 C,

280/11.13 L; 9/310; 272/565 SS, 57 B,

[56] References Cited UNITED STATES PATENTS 2.251.927 8/1941 Ermel 272/56.5 SS UX 3,120,385 2/1964 Hall 272/565 SS 3,159,400 12/1964 Brass et al... 272/57 B 3,164,247 l/l965 Hall 272/565 SS 3,395,411 8/1968 Pope et al 280/1 1.13 S X FOREIGN PATENTS OR APPLICATIONS 1,086,010 6/1953 France 272/565 ss Primary Examiner-M. Henson Wood, Jr. Assistant Emminer-Gene A. Church Attorney, Agent, or FirmWil1iam Anthony Drucker [57] ABSTRACT A ski is provided on its under surface with a longitudinal central part having a smoother surface configuration than the adjacent surfaces and this ski is to be used on a substantially hard smooth surface especially on an inclined belt which can be adjusted as to speed and inclination.

10 Claims, 6 Drawing Figures PATENTEDJUN 191 (1814.417

SHEET 3 [IF 3 SKI AND SKI PRACTICE MACHINE This invention relates to skis and ski practising apparatus simulating skiing on snow.

Snow has the property of packing to a surface on which one can ski but movable in small quantities under the action of the ski and capable of reforming as a firm surface in the position to which it has been moved. This property enables skiers to pass over the same surface area but on each successive pass the snow will present itself to the under surface of the skis in a different quantity and density.

Each skier uses the snow over which he passes in a variety of different ways depending on the angle at which he presents the under-side of his skis. He will collect a quantity of this material under the skis to form a wedge which he uses to control his direction and speed against the natural forces of gravity. At any speed and in any direction the snow forming the wedge will be collected from the down-side of the skis and will be deposited continuously on the upperside of the skis.

Attempts to reproduce this property with any substance other than natural snow have centred on a bristle formation on a solid base so that a collection of bristles on the under-side of the ski at any one pass will successively a. meet the lower edge of the ski in an upright position that is, at 90 to the angle of the slope on which it is laid b. bend under pressure from the ski down the slope in such a way that all the bristles in contact with the under-side of the ski at any one moment are held in a position of less than 90, thus forming the necessary wedge.

c. return to their original position of 90 to the angle of the slope when the pressure from the ski has been relieved.

This type of simulation while being the best available has the disadvantages of being subject to deterioration in such a way that the bristles assume a position of less than 90 to the slope after a period of usage. The

coefficient of friction in the downhill running position is such that the skis run too fast and without any real control and attempted manoeuvres to the left or right of the fall-line rely on the perfect positioning of the skis in their relationship to the surface and the continued perfect condition of the surface itself. Neither of these conditions is likely to prevail for any length of time when the ability of the skier and the properties of the artificial slope are taken into consideration.

It has been proposed to provide a ski practice surface in the form of a continuous belt having the ski surface formed of deep pile nylon fabric of loops to enable the edge of the ski to sink therein to afford edge control.

An object of the present invention is to provide a ski for use on a substantially non-indenting ski surface.

According to the present invention a ski is provided on its under surface with a longitudinal central part having a smoother surface configuration than the adjacent longitudinal surfaces on either side of the central part, said adjacent surfaces being at a higher level than the central part. The adjacent surfaces may be provided with a series of ribs and corresponding grooves between them located longitudinally of the ski adjacent the sides thereof. Each of the ribbed parts may extend over 15 to 35 per cent or more (preferably 15 to 30 per cent) of the width of the ski. Between the ribbed parts the ski may have a central part curved transversely which extends longitudinally of the ski and may extend over 25 to per cent of the width of the ski (preferably 28 to 40 per cent) leaving a flat part between the ribs on each side and the curved part. The lower surfaces of the ribs on each side may form a curve or plane which is higher at the edges.

It is an important feature of the present invention that whereas heretofore the ski practice slope has been provided with bristles or other deeply indenting means enabling the ski to sink therein to provide edge control, this is now obtained in accordance with our invention by using a substantially nonindenting moving ski surface in combination with a ski which has parts of its undersurface provided with a central part and adjacent surfaces of such surface configuration as to provide increased friction compared with the central part thereby affording the required lateral control or braking. Moreover, whereas the practice slopes made of bristles and other deeply indenting material necessitated the use of a very thick and heavy material and consequential heavily built apparatus for driving it the present invention permits the use of comparatively light weight material and a much less cumbersome and cheaper apparatus. This also makes it practicable to provide means whereby the speed of the belt and its inclination can be varied by the user while skiing on the belt.

The invention is illustrated by way of example with reference to the accompanying drawings wherein:

FIG. 1 is an underneath plan view of a ski made in accordance with the invention;

FIG. 2 is a side elevation thereof;

FIG. 3 is a rear view thereof.

FIG. 4 is a side elevation of a ski practice apparatus;

FIG. 5 is a plan view thereof; and

HG. 6 is a sketch of a woven fabric material for use in the apparatus A normal ski 7 is moulded in one piece in a synthetic plastics material, e.g., Perspex. Attached by screws 8 to the underneath of the ski 7 is a ski plate 9 which has a series of ribs 10 on its under surface at each side adjacent the edge and extending from front to rear longitudinally of the ski with corresponding grooves between the ribs. The parts 7, 9 may be made integrally if desired. The lower surfaces of the ribs may have a width of 1/8 to 1/4 inch, e.g., three sixteenths and the grooves may have about the same width at their upper surfaces. Between the ribbed parts and centrally of the bottom of the ski is a curved smooth part 12 with its lowest part extending on the longitudinal centre line of the ski. This part hasa width of about 30 to 35 percent of the width of the ski. The ski has the usual pointed and upturned front end 13 and has holes 14 for attachment of boot fixing devices 16, 17. The ski is flat from its front curved end to its rear edge. The bottom surfaces of the ribs 10 at each side of the central part are progressively lower from the outer edge inwards so that they lie on a curve or plane which is highest at the edge of the ski.

The central part 12 is at a lower level than the adjacent ribbed parts and is smooth and is used for normal ski running while the ribbed parts provided increased friction with the ski slope surface when required for braking or control.

Instead of ribs we may provide numerous'small studs or other projectionsor roughness, i.e., any surface configuration providing a frictional engagement with the skiiing surface greater than that of the smooth central part.

The ski practice machine shown in FIGS. 4 and 5 comprises an endless belt carried on rollers 21, 22, the roller 22 being mounted at a higher level than the roller 21. The lower roller'2l has a spindle 24 mounted in bearings 25, 26. The spindle 24 carries a sprocket 28 that is driven by chain 29, sprocket 30, variable speed gearbox 31 and electric motor 32. The upper roller 22 has a spindle 34 mounted in a bearing and adjustable for tensioning the belt by screw 35. The bearings of the rollers are carried by a framework 37 the lower end of which is mounted on a stand 38, and base plate 39 and the upper end of which is carried bya vertically adjustable arm 40 adjustment of which varies the inclination of the belt. The arm carries a nut 41 engaging a screwed rod 42 that is mounted on a frame 43 pivoted at 44 on lugs 45 onthe base plate 39. The rod 42 can be rotated by bevel gears 47, 48, gearbox 49 and electric motor 50.

The variable speed gearbox 31 is controlled by means of arotatable knob 51 and the motor 32 can be started and stopped by control buttons 53, 54. The gearbox 49 can be controlled by buttons 55, 56,57 for up, stop and down. All the control buttons are positioned so that they can be reached by the skier while skiing on the belt and for this purpose are supported by an upstanding frame 60 carried on the framework 37. The frame 43 carries an arm 61 operating microswitches 62, 63 for stopping the motor 49 at the upper and lower limits of travel of the nut 41.

Screws 65, 66 are provided for adjusting the position of the gearbox 31 and motor 32 for adjusting the tension of the chain 29.

The spindle 24 is connected by sleeve 68 to the spindle 69 of an adjacent similar machine.

The frame 60 carries platforms 70, 71 on opposite sides of the moving belt.

The belt is made of closely woven strands of synthetic plastics material as shown in FIG. 6 having longitudinal strands 73 and transverse strands 74 interwoven with various thinner strands at 75. The material is substantially non-indenting. under the pressure of the ski.

The material may be a basket weave of a polyamide or polypropylene fabric, e.g., material known as PPF 40" about 1/8 to H4 inch thickness. A similar material may be moulded with indulating surface resembling the fabric.

A switch lever 77 is pivoted to the rear of the frame at 78 and extends across the width of the belt 20. This lever is arranged'to switch'off the current to the belt motor 32 should the skier be carried to the top of belt, e.g., should he fall.

1. in combination a snow ski and a ski practice machine, for practicing snow skiing, the ski being provided on its under surface with a longitudinal central part having a smoother surface configuration than the adjacent longitudinal surfaces on either side of the central part, said adjacent surfaces being at a higher level than the central part; and said machine having'a continuously driven endless belt the ski surface of which consists of a substantially non-indenting material with slightly undulating surface.

2. A combination as claimed in claim 1 wherein the said adjacent surfaces are provided with a series of ribs and corresponding grooves between them located longitudinally of the ski.

3. A combination as claimed in claim 2 wherein each of the ribbed'parts extends over 15 to 35 per cent of the width of the ski.

4. A combination as claimed in claim 1 wherein the central part is curved transversely.

5. A combination as claimed in claim 4 wherein the curved part extends over 25 to per cent of the width of the ski.

6. A combination as claimed in claim 2 wherein the bottom surfaces of the ribs are at each side of the central part progressively lower from the outer edge inwards so that they lie on a curve or plane which is highest at the edge of the ski.

7. A combination as claimed in claim 1 wherein the said material is a woven synthetic plastics material.

8. A combination as claimed in claim 13 wherein the said material is a synthetic plastics material moulded to simulate a woven material.

9. A combination as claimed in claim 1 having means whereby the user can vary the speed of the belt and its inclination whilst skiing on the belt.

10. A combination as claimed in claim 1 wherein the belt is driven by an electric motor and a movable switch control member is provided at the top of the belt whereby the belt is stopped if the skier falls and is carried up to the top of the belt. 

1. In combination a snow ski and a ski practice machine, for practicing snow skiing, the ski being provided on its under surface with a longitudinal central part having a smoother surface configuration than the adjacent longitudinal surfaces on either side of the central part, said adjacent surfaces being at a higher level than the central part; and said machine having a continuously driven endless belt the ski surface of which consists of a substantially non-indenting material with slightly undulating surface.
 2. A combination as claimed in claim 1 wherein the said adjacent surfaces are provided with a series of ribs and corresponding grooves between them located longitudinally of the ski.
 3. A combination as claimed in claim 2 wherein each of the ribbed parts extends over 15 to 35 per cent of the width of the ski.
 4. A combination as claimed in claim 1 wherein the central part is curved transversely.
 5. A combination as claimed in claim 4 wherein the curved part extends over 25 to 60 per cent of the width of the ski.
 6. A combination as claimed in claim 2 wherein the bottom surfaces of the ribs are at each side of the central part progressively lower from the outer edge inwards so that they lie on a curve or plane which is highest at the edge oF the ski.
 7. A combination as claimed in claim 1 wherein the said material is a woven synthetic plastics material.
 8. A combination as claimed in claim 13 wherein the said material is a synthetic plastics material moulded to simulate a woven material.
 9. A combination as claimed in claim 1 having means whereby the user can vary the speed of the belt and its inclination whilst skiing on the belt.
 10. A combination as claimed in claim 1 wherein the belt is driven by an electric motor and a movable switch control member is provided at the top of the belt whereby the belt is stopped if the skier falls and is carried up to the top of the belt. 